Expression of recombinant classical swine fever virus E2 glycoprotein by endogenous Txnip promoter in stable transgenic CHO cells

Abstract

As the main immunogen that could stimulate neutralized antibody in pigs, recombinant E2 protein of CSFV was expressed in CHO‐dhfr−cells driven by endogenous Txnip promoter from Chinese hamster. Different fragments of Txnip promoter were amplified by PCR from isolated genomic DNA of CHO cells and cloned into different expression vectors. Compared with CMV promoter, CHO‐pTxnip‐4‐rE2 (F12) cell clone with the highest yield of rE2 protein was established by random insertion of the expression cassette driven by 860 bp sequences of Txnip promoter. In combination with treatment of 800 nM MTX for copy amplification of inserted expression cassette, the dynamic expression profile of rE2 protein was observed. Then inducible expression strategy of balance between viable cell density and product yield was conducted by mixed addition of 0.1 mM NADH and 0.1 mM ATP in culture medium at day 3 of batch‐wise culture. It could be concluded that Txnip promoter would be a promising alternative promoter for recombinant antigen protein expression in transgenic cells.

Efficacy evaluation of a bivalent subunit vaccine against classical swine fever virus and porcine circovirus type 2

“…Mammalian cells, especially CHO cell line, have been considered as the optimal host cells for the production of antibodies, cytokines, and viral antigens. Recently, Feng et al developed stable transgenic CHO cells to express recombinant CSFV E2 protein 29 . In this study, the E2 antigen was expressed by stable clones derived from CHO cells followed by a series of purification processes to yield high-quality pure E2 proteins.…”

A Self-Assembling Ferritin Nanoplatform for Designing Classical Swine Fever Vaccine: Elicitation of Potent Neutralizing Antibody

“…The structural glycoprotein E2 of CSFV produces a predominant and efficacious humoral immune response of neutralizing antibodies and is the main cellular immunity inducer of specific CD8+ effector cytotoxic T lymphocytes [ 3 , 4 ]. However, a CSFV lapinized vaccine C-strain against CSF globally lacks the capability of serological differentiation between infected and vaccinated animals (DIVA) [ 5 ].…”